It is known from U.S. Pat. No. 3,530,168 to contact an olefin, carbon monoxide and oxygen with an alcoholic solution of a catalyst comprising a Group VIII noble metal, a biphyllic ligand and a redox agent, to prepare mono- and diesters of saturated and unsaturated carboxylic acids having one more carbon atom than the olefin reactant. The examples in this patent show that esters of monocarboxylic acids were obtained in a relatively low yield, calculated on starting olefin.
According to the non pre-published British Patent Application No. 8602177, an optionally substituted ethylenically unsaturated hydrocarbon is reacted with carbon monoxide and an alcohol in the presence of a catalyst comprising a Group VIII noble metal, a quinone and a redox agent, to prepare diesters of dicarboxylic acids. This process is preferably carried out at a pressure in the range of from 5 to 200 bar, so as to obtain said diesters in a very high yield.
It has now been found that by using special starting ethylenically unsaturated hydrocarbons at a relatively low partial pressure of carbon monoxide, esters of mono-carboxylic acids are obtained in a high yield.